Molecular Quality Controls

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Discover Independent QC

The right QC is about what laboratories should do to ensure that patient results are correct and reliable for their intended use. 1

What is an independent quality control?
Independent quality controls provide an unbiased, independent assessment of a test system or method performance because they are manufactured independently of the instrument, reagents and calibrators.
Why should I use an independent quality control?
Many instrument manufacturers provide both calibrators and control materials for their own systems. These controls are designed for use only on their own test systems, but more importantly, they are often manufactured from the same materials as the calibrators. Consequently, the control may mimic the calibrator, making it less sensitive to changes in device performance. This can lead to acceptance of patient test results with analytical error that could be medically important. 

Conversely, independent quality controls which are more like patient samples, may be better able to detect performance shifts. This can increase confidence in reported patient results.
Why should I use an independent quality control instead of patient sample pools to monitor assay performance?
Independent quality controls are manufactured under strict quality standard protocols and procedures, providing reliability and reproducibility. They offer consistency from lot to lot and can be used long-term without the need for constant evaluations and protocol alterations.

Patient pools on the other hand, may not be handled in accordance to any specific guidelines or regulations. Utilizing these sample pools can become a time consuming endeavor if appropriate low positive samples cannot be identified for testing. 



This approach also prevents data comparison with other laboratories using an interlaboratory program because in order to do so, the labs must share a common pool, which an independent quality control would provide.
Are there risks associated with only using manufacturer or in-kit controls?
Instrument manufacturer or in-kit controls are designed only for use on specific test systems for which they are made. They are often manufactured from the same materials as their calibrators, making them less sensitive to changes in device performance. This can lead to acceptance of patient test results with analytical errors that could be medically important.
Additional Resources:

1 James O. Westgard, Perspectives on Quality Control, Risk Management, and Analytical Quality Management. Quality Control in the Age of Risk Management, James O. Westgard and Sten Westgard, editors, Clinics in Laboratory Medicine Vol 33, no. 1, p. 3 (2013), Elsevier, Philadelphia.